A novel genetic method MALD has been proposed and implemented in the laboratory which provides a population- and patient cohort-based approach for disease gene identification. The method uses genetic markers with significant allele frequency differences between racial groups that we have developed. In combination with a population that has a recent history of admixture one can identify novel disease genes underlying racial disparities in patient cohorts. This methodology is particularly appropriate for diseases where collecting large families for linkage analysis is difficult or where disease onset involves exposure to a common environmental or infectious agent. We have been collecting and analyzing samples from African American patients for hepatitis C virus (HCV) clearance, HIV-1/AIDS, focal segmental glomerulosclerosis, and end-stage renal disease. These diseases are currently ongoing MALD mapping, statistical analysis and fine mapping of signals for gene localization and identification.